UICollectionView和补充视图崩溃 [英] UICollectionView and Supplementary View crash

问题描述

我有一个工作正常的UICollectioView. 有两种访问此页面的方法.

I have a UICollectioView that works fine. There are 2 ways to get to this page.

1. 虽然是应用程序.
2. 点击推送通知.

除了一个案例，一切都很好.

Everything works good except one case.

如果用户正在聊天，然后退出应用程序(主页按钮) 然后他会收到一个推送通知，按下该通知，应用就会崩溃.

if the user is in the chat and then he exits the app (home button) then he gets a push notification he presses it and the the app crashes.

崩溃:

2015-09-25 10:28:15.140 Quest [298:16922] *断言失败 -[UICollectionView _createPreparedSupplementaryViewForElementOfKind:atIndexPath:withLayoutAttributes:applyAttributes:]， /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKit/UIKit-3505.16/UICollectionView.m:1519 2015-09-25 10:28:15.146 Quest [298:16922] * 由于以下原因终止了应用 未捕获的异常"NSInternalInconsistencyException"，原因: 未设置UICollectionView数据源" ***第一个抛出调用堆栈:(0x1828b4f5c 0x1973b7f80 0x1828b4e2c 0x1837a3f3c 0x187f97a38 0x187e6ebd4 0x187e6fb54 0x187e69b88 0x187e0700c 0x18760df14 0x187608b20 0x1876089e0 0x18760807c 0x187607dd0 0x1880c0bd4 0x18286c48c 0x18286bdc4 0x182869d4c 0x182798dc0 0x18d8ec088 0x187e72f60 0x100215590 0x197be28b8) libc ++ abi.dylib:以类型未捕获的异常终止 NSException

2015-09-25 10:28:15.140 Quest[298:16922] * Assertion failure in -[UICollectionView _createPreparedSupplementaryViewForElementOfKind:atIndexPath:withLayoutAttributes:applyAttributes:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKit/UIKit-3505.16/UICollectionView.m:1519 2015-09-25 10:28:15.146 Quest[298:16922] * Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UICollectionView dataSource is not set' *** First throw call stack: (0x1828b4f5c 0x1973b7f80 0x1828b4e2c 0x1837a3f3c 0x187f97a38 0x187e6ebd4 0x187e6fb54 0x187e69b88 0x187e0700c 0x18760df14 0x187608b20 0x1876089e0 0x18760807c 0x187607dd0 0x1880c0bd4 0x18286c48c 0x18286bdc4 0x182869d4c 0x182798dc0 0x18d8ec088 0x187e72f60 0x100215590 0x197be28b8) libc++abi.dylib: terminating with uncaught exception of type NSException

推送处理程序中的代码:

code in push handler:

func application(application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject : AnyObject]) {

                let home = storyboard.instantiateViewControllerWithIdentifier("home") as! HomeViewController
                let chat = storyboard.instantiateViewControllerWithIdentifier("chat") as! ChatViewController

                var controllers : [UIViewController] = [login, chat]
                NotificationManager.handleNotification(userInfo, controllers: &controllers, storyboard: storyboard)
                navC.viewControllers = controllers
                self.window?.makeKeyAndVisible()

}

collectioview设置代码

collectioview setting code

@IBOutlet weak var chatCollectionView: UICollectionView! {
    didSet {
        chatCollectionView.registerNib(UINib(nibName: "ChatTimeStampCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: "ChatTimeStampCell")
        chatCollectionView.registerNib(UINib(nibName: "ChatReceiverCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: "ChatReceiverCell")
        chatCollectionView.registerNib(UINib(nibName: "ChatSenderCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: "ChatSenderCell")
        chatCollectionView.registerNib(UINib(nibName: "ChatHeaderCollectionReusableView", bundle: nil), forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "ChatHeaderCell")

        chatCollectionView.dataSource = self
        chatCollectionView.delegate = self
    }
}

推荐答案

如果您在集合视图中使用自定义布局，请检查其数据源是否为nil in

If you are using custom layout in your collection view, check if its datasource is nil in:

- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect

结果应如下所示:

- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect
    if (self.collectionView.dataSource != nil) {
        // Your layout code    
        return array;
    }
    return nil;
}

此更改解决了以下问题:

This change resolves the following issue:

• -[UICollectionView _createPreparedSupplementaryViewForElementOfKind:atIndexPath:withLayoutAttributes:applyAttributes:]中的断言失败

• Assertion failure in -[UICollectionView _createPreparedSupplementaryViewForElementOfKind:atIndexPath:withLayoutAttributes:applyAttributes:]

您还可以检查以下主题，但是在我看来，它们没有解决任何问题: UICollectionView和补充视图(标题)

You can also check the following topics, however they didn't resolve anything in my case: UICollectionView and Supplementary View (header)

如果删除空白空间，如果该节标题隐藏在UICollectionView中

希望它能对您有所帮助，并且您不会像我那样浪费太多时间. @eeeee感谢您为我指出正确的方向.

Hope it will help you, and you won't waste as much time as I did. @eeeee thank you for pointing me in the right direction.

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